Claims
- 1. The method for treating a surface with a treatment gel, said method comprising in this order the following steps:
applying a treatment gel on the surface to be treated, said treatment gel consisting of a colloidal solution comprising:
5 to 25% by weight, based on the weight of the gel, of a mixture of pyrogenated silica and precipitated silica, 0.5 to 4 mol/l of an active treatment agent, and optionally from 0.05 to 1 mol/l of an oxidizing agent having a normal oxidation-reduction potential E0 larger than 1.4 V in a strong acid medium or of the reduced form of this oxidizing agent, maintaining the treatment gel on the surface to be treated at a temperature and relative humidity such that the gel dries and that it has the time to treat the surface before forming a dry and solid residue, and removing the dry and solid residue from the treated surface.
- 2. The treatment method according to claim 1 wherein the drying temperature is between 20 and 30° C., and the relative humidity between 20 and 70%.
- 3. The treatment method according to claim 1, wherein the silica mixture represents 5 to 15% by weight of the gel.
- 4. The treatment method according to claim 1, wherein the silica mixture represents 5 to 10% by weight of the gel.
- 5. The treatment method according to claim 1, wherein the precipitated silica represents 0.5% by weight of the gel and the pyrogenated silica represents 8% by weight of the gel.
- 6. The treatment method according to claim 1, wherein the active treatment agent is an inorganic acid or a mixture of inorganic acids.
- 7. The treatment method according to claim 6, wherein the inorganic acid is selected from hydrochloric acid, nitric acid, sulfuric acid, phosphoric acid or a mixture thereof.
- 8. The treatment method according to claim 1, wherein the gel comprises an active treatment agent which is an inorganic base present in a concentration from 0.5 to 2 moles per liter of gel.
- 9. The treatment method according claim 8, wherein the inorganic base is selected from soda, potash or a mixture thereof.
- 10. The treatment method according to claim 1, wherein the treatment gel comprises from 0.5 to 1 mol/l of an oxidizing agent with a normal oxidation-reduction potential E0 larger than 1.4 V in a strong acid medium selected from Ce(IV), Co(III), or Ag(II).
- 11. The treatment method according to claims 1, wherein the treatment gel comprises from 5 to 15% by weight of silica, from 0.5 to 2 mol/l of nitric acid, and from 0.1 to 0.5 mol per liter of gel, of Ce(NO3)4 or (NH4)2Ce(NO3)6.
- 12. The treatment method according to claim 1, wherein the treatment gel is applied on the surface to be treated in an amount from 100 to 2,000 g of gel per square meter of surface.
- 13. The method according to claim 1, wherein the dry and solid residue is removed from the treated surface by brushing and/or by suction.
- 14. The use of a method according to claim 1, for degreasing a surface, for removing an oxide layer from a metal surface or for decontaminating a surface.
- 15. The method for decontaminating a facility, comprising removal of dust from the facility to be treated, followed by a treatment of the facility by means of a method according to claim 1.
- 16. The method according to claim 15, wherein the facility is a ventilation shaft of a nuclear facility.
- 17. A gel for treating a surface consisting of a colloidal solution comprising:
5 to 25% by weight, based on the weight of a gel, of a mixture of pyrogenated silica and precipitated silica, 0.5 to 4 mol/l of an active treatment agent, and optionally 0.05 to 1 mol/l of an oxidizing agent with a normal oxidation-reduction potential E0 larger than 1.4 V in a strong acid medium or of the reduced form of this oxidizing agent.
- 18. The gel for treating a surface according to claim 17,
wherein the silica mixture represents 5 to 15% by weight based on the weight of the gel; and wherein the active treatment agent is an inorganic acid or a mixture of inorganic acids.
- 19. The treatment gel according to claim 17, wherein the mixture of pyrogenated and precipitated silicas represents 5 to 10% by weight of the gel.
- 20. The treatment gel according to claim 17, wherein the precipitated silica accounts 0.5% by weight of the gel and the pyrogenated silica represents 8% by weight of the gel.
- 21. The treatment gel according to claim 18, wherein the inorganic acid is selected from hydrochloric acid, nitric acid, sulfuric acid, phosphoric acid or a mixture thereof.
- 22. The treatment gel according to claim 17, wherein the oxidizing agent with a normal oxidation-reduction potential E0 larger than 1.4 V in a strong acid medium is selected from Ce(IV), Co(III) or Ag(II).
- 23. The treatment gel according to claim 20, wherein the oxidizing agent with a normal oxidation-reduction potential E0 larger than 1.4 V in a strong acid medium is selected from Ce(IV), Co(III) or Ag(II).
Priority Claims (1)
Number |
Date |
Country |
Kind |
01/9520 |
Jul 2001 |
FR |
|
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority based on international patent application no. PCT/FR02/02509, entitled “Method For Treating a Surface With a Treatment Gel, and Treatment Gel” by Sylvain Faure, Bruno Fournel, Paul Furntes and Yvan Lallot, which claims priority of French Application No. 01 09520, filed on Jul. 17, 2001, and which was not published in English.
PCT Information
Filing Document |
Filing Date |
Country |
Kind |
PCT/FR02/02509 |
7/15/2002 |
WO |
|